Air-draft system for steam-boilers.



No. 871,541 PATENTED NOV. 19, 1907.

. W. 0. WALLACE.

AIR DRAFT SYSTEM FOR STEAM BOILERS.

- APPLICATION FILED JULY 7. 1 906.

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WITNESSES H I I'NVE NTOR 1 5% M I tddaxm Mum ATTORNEYS W. G. WALLACE.

AIR DRAFT SYSTEM FOR STEAM BOILERS. APPLIOATION FILED JULY 7. 190a.

- 8 SHEETS-SHEET 2 wmaessts \NVENTOR M A MMMVMI ATTORH EYS PATENTED NOV. 19 1907.

No. 871,541. PATENTED NOV. 19, 1907. 0. WALLAUEL' AIR DRAFT SYSTEM FOR STEAM BOILERS.

APPLICATION FILED JULY7. 1906.

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N \TNESSES \NVENTOR ATTORNEYS Be it knownethat 1, WILLIAM WILLIAM CARLI LE WALLACE, OF TENAFLY, NEW JERSEY, ASSIGNOR OF ONE-HALF TO JOHN BROWN & COMPANY, LIMITED, OF SHEFFIELD, ENGLAND.

AIR-DRAFT sxs'rnm Fon STEAM-BOILERS.

To all whom it may concern:

OARLILE WALLACE, a subject of the King of Great tion.

A The boiler A 2 5 1 as having front elevation partly in section;

Britain and Ireland, and a resident of Tenafiy, Bergen county, New Jersey, have invented certain new and-useful Improvements in Air-Draft Systems for Steam-Boiler Furnaces, of which the following is a specification.

Myinvention relates more particularly to draft systems for steam boiler furnaces of that class in which forced draft is combined with suction draft. The object of my invention is'to improve 'and simplify such apparatus and to so construct it that it will be automatic inits ac- In the accompanying drawings Figure 1 is aside .elevation partly in section (onithe line 1-1,Figs. 2 and 3) of a marine boiler furnace' with my improvements; Fig. 2 is a and Fig. 3. is -a plan view.

the furnace doors at a and the smoke flues at B leading up to the chimney or stack 0. on the Way the products of corn- I bustion pass through the tubesd of an air heater; D, which 1 structlon forming prefer to make of the con- Q 1 of the .heater from the air chamberE, and

or furthen descending-ground the tubes to the air chambers f lea Iiaces F, Fig. 2.

' g" to the. fire, places,

Onthe'top of the boiler or on any suitable support I mount a duplex fan G, whose blades air inlet h. The chamber in which the blades are carried on the end .duplex casing H, which side has a central inlet k the duplex fan chamber,

in bearings s on the frame work, andcoupled to the driving shaft of a steam engine or other motor M. The two sets of blades g, fans are separated from each other. by a partition g revolving with the blades. The

blades and this partition revolve within a on the right hand from the smoke flue B and on the opposite side has a central fresh 9 revolve has its discharge outlet at b i'nto the smoke stack, While the discharge'outlet from-late other fan chamber is at 6 into the air or econo y of manufacture m the building of Specification of Letters Patent. Application filed July 7. 1906- Serial No. 325.140.

- out near the air inlet h to the force and furnace maybe of anyusual or suitable construction. It Is shown the subject of my Patent No. "659,561 the air entering the upper part of a shaft S mounted 9 of the e leading tothe air chamber E. For

these two discharge Patented Nov. 19, 1907.

outlets b and 6 may be alongside each other as shown, but if preferred, two parts of the fan may discharge. at different circumferential pomts of the fan casing.'- The central partition g? of the revolving part of the fan is preferably arranged to extend radially beyond the fan blades and to overlap a fixed partition is in the fan casing-H, the revolving partition being on the fair-chamber side as thatis the side in which there'is the greater pressure.

. In the'smoke flueB, I provide a damper b, by adjustin which the action of the suction part'of t e fan may be regulated. -I may also plt'ovide a by-pass pipe N leadingfrom the c part of the fan, this pipe-bein rovided with a dam er n, on opening whic a art of the ases rom the smoke flue may e carried ack with the draft of, fresh, air to the furnaces, to be consumed. The fresh air is forced by the blades 9 through the air duct e to the chamber E, and thence through the heater D toithe furnaces, and on the other hand the blades g suck the ases from the furnaces to give a suction dra t in exact proportion to the forced draft, since the two sets of blades of the fan necessarily revolve at the same speed.

Iclaim as my invention a 1. The combination of a furnace having an mney or smoke flue and o ening draft air heater in the smoke fine with a do lex fan, flue connections whereby one part 0 the fan applies SUClLlOIi draft to the gases in the smoke flue above the airheater, and with air connections whereby the other part of the fan forces fresh air to the heater and thence to the furnace, said fan comprising a duplex chamber and .a fixed partition and revolving blades and a dividing partition revolving withthem. I

' 2. The combination'of a furnace having an air heater in thesmoke flue with a du lex fan, flue connections whereby one part 0 the fan applies'suction draft to the gases in the smoke flue above the air heater, and with air connections whereby the other part of the fan forces fresh air to the-heater and thence to the furnace, said fan comprising a duplex chamber and a fixed partition and revolving blades and a dividin partition revolving withthem, this dividmg artition overla pringl the edge of the fixe partitionon 't e es an slde.

3. The combination of afurnace having an In testimony whereof I have signed my 10 air heater in the smoke flue with a duplex name to this specification, in the presence of fan, and fine connections to apply suction two subscribing Witnesses. draft-to the gases in the smoke flue ebo ethe i 5 air heater, and to force fresh air to the heater I WILLIAM GARLlLE WALLACE,

and thence to the furnace, and a by-pasS pipe leading from the smoke flue and opening to Witnesses: v the fresh air inlet to the fan and provided I .C. SEDGWIOK, With a damper, HUBERT HowsoN; 

